CVE-2023-27956

Process-memory disclosure via crafted image parsing

Published May 8, 2023 · Updated Jan 29, 2025

Memory-handling flaw in Apple FontParser allows attackers to disclose process memory by processing a maliciously crafted image. FontParser performs an undisclosed incorrect memory operation while decoding attacker-controlled image data; Apple has not published the affected function or access boundary. Exploitation requires a user or application to process the image, and the documented consequence is limited to contents of the affected process's memory.

CVSS severity5.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory-handling flaw in Apple FontParser allows attackers to disclose process memory by processing a maliciously crafted image. FontParser performs an undisclosed incorrect memory operation while decoding attacker-controlled image data; Apple has not published the affected function or access boundary. Exploitation requires a user or application to process the image, and the documented consequence is limited to contents of the affected process's memory.

The record

CVE
CVE-2023-27956
Published
May 8, 2023
Updated
Jan 29, 2025
Vendor
Apple
Product
iOS and iPadOS
Classifications
CWE-120, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 29, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <15.7
  2. Affected versionversion=unspecified <16.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Apple · iOS and iPadOSversion=unspecified <15.7; version=unspecified <16.4
Apple · tvOSversion=unspecified <16.4
Apple · macOSversion=unspecified <13.3
Apple · watchOSversion=unspecified <9.4

Published CVSS scores

5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
5.5NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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